I. Field of the Invention
This invention relates to optical devices for adding and dropping optical signals to an optical fiber carrying existing optical signals without interfering with the existing optical signals. More particularly, the present invention is directed to a wavelength division multiplex add/drop optical device using a micromirror array for transmitting and reflecting optical signals in an optical communications system.
II. Description of the Related Art
In wavelength division multiplexed optical networks it is increasingly important to be able to switch multiple independent wavelength signals into and out of a single fiber without disturbing the other channels. This task is presently accomplished by utilizing an assembly of separate components such as a pair of wavelength demultiplexers and a set of N two-by-two bypass exchange switches. As is known, one of the wavelength demultiplexers, also known as a router, separates a multifrequency optical input data signal into N multiple fibers, with each fiber carrying a single wavelength. The bypass exchange switches accept the added and dropped channels. The other wavelength multiplexer combines the existing wavelengths with the added wavelengths onto a single fiber for transmission in the communications system. Among the drawbacks of such a discrete component approach, however, are the cost and size of the individual components and the resulting overall cost and size of the system.